Polyamide compositions are known to exhibit enhanced high temperature properties and are widely used as engineering plastic molding materials. Such compositions, however, have poor melt strength and are difficult to process by blow molding, the process which is most commonly used on an industrial scale to form hollow containers. Consequently, hollow polyamide containers which have outstanding high temperature properties have not been readily available.
One solution to this problem has been to blend the polyamide compositions with materials which increase melt strength and modify melt viscosity. For example, it is disclosed in U.S. Pat. No. 4,804,703 that when mixtures of fibrillatable fluoropolymer resins and ionic copolymers of ethylene with alpha, beta-unsaturated carboxylic acids are added to mineral-reinforced semi-crystalline polyamides compositions are produced which are readily processible by blow molding. Mineral reinforced polyamides are, however, quite stiff compositions which are not suited for use in applications in which a substantial amount of flexibility is required, such as impact-resistant containers, especially large containers which are designed for applications in which both high and low temperatures are encountered, for example automotive air ducts and resonators. Thus, there exists a need in the art for a polyamide composition which has outstanding properties over a broad range of temperatures, and, in addition, is flexible as well as blow moldable.